1. Field of the Invention
Exemplary embodiments of the present invention relate to a liquid crystal display and a method for repairing a defective pixel, more particularly, to a liquid crystal display capable of performing a repair by implementing a repairing process for curing the defective pixel electrode while ensuring the maximum aperture ratio, and a method for repairing the defective pixel electrode.
2. Description of the Background
In general, a liquid crystal display (LCD) has been adopted as one of the most widely used types of flat panel displays (FPDs) attributed to several advantages, for example, a mobility with a slim and a lightweight profile, low power consumption by a low driving voltage.
The LCD typically includes a color filter substrate having a common electrode and color filters formed thereon, a thin film transistor substrate having thin film transistors and pixel electrodes, and a liquid crystal layer interposed therebetween. Different voltages are applied to the common electrode and the pixel electrodes to create an electric field in the liquid crystal layer, and arrangement of liquid crystal molecules in the liquid crystal layer varies, thereby displaying an image.
Conventionally, in order to repair a defective pixel electrode of the LCD, a sustain electrode line provides for creating storage capacitance Cst. More specifically, the defective pixel electrode is repaired by cutting a drain electrode connected to the defective pixel electrode so that the defective pixel electrode is turned into a floating state and cutting the defective pixel electrode while in the floating state from the sustain electrode line.
In general, a voltage equal to a common voltage supplied to a common electrode of a color filter substrate is also applied to a sustain electrode line. In such a manner, the common electrode and a defective pixel electrode may have the same electric potential by shorting the defective pixel electrode from a sustain electrode line, thereby converting the defective pixel electrode into an off-pixel.
An approach has been introduced to increase the aperture ratio of an LCD while significantly reducing the width of a sustain electrode line or even eliminating the sustain electrode line. This approach can be compensated for by interposing liquid crystal molecules with high dielectric constant.
However, this approach can cause defective pixel shorting problems because efforts for increasing aperture ratio are eventually lead to eliminating a sustain electrode line, which may cause difficulty in repairing defective pixels.